两种幼龄乔木修复林下土壤改良及植被多样性研究

以辽宁省抚顺市榆树铁矿和傲牛铁矿植被恢复区为研究对象, 两矿山分别选用先锋树种樟子松和刺槐进行单纯乔木层植被修复。通过调查样方植被株高及胸径、测定土壤指标, 参照全国第二次土壤普查分级标准分析两矿山已恢复样地土壤肥力状况, 再综合香农-维纳多样性指数和德尔菲法确定的指标权重计算植被多样性指数, 进而分析恢复初期林下草本层植被多样性及土壤基质变化情况。结果表明: 幼龄林恢复期间, 樟子松和刺槐的胸径和树高逐年升高, 刺槐年均树高增长可达樟子松的1.94—4.43倍, 两种乔木均可将酸性土壤改良至中性, 但幼龄樟子松林较幼龄刺槐林更易积累贫瘠地中的营养物质; 植被多样性调查共出现19种草本植物, 隶属于11科16属, 植被多样性评价显示刺槐林草本层植被多样性指数均高于樟子松林。综上, 推荐抚顺市废弃矿山乔木层混交种植樟子松和刺槐, 以共同作用促进草本层自然演替过程, 并引入灌木种形成“乔-灌-草”复合系统加快矿山修复进程。     

湘南红壤丘陵区不同植被类型下土壤肥力特征

以自然植被恢复长期定位试验为基础,通过分析自然恢复31a后形成的6个植被类型区(樟树、枫树、梓树、白檵木、唐竹、白茅草)、2个同期种植的人工植被区(湿地松、板栗)以及相邻裸地区0—100 cm土层pH值、有机质及主要养分含量的变化,明确了湘南红壤丘陵区不同植被类型对土壤肥力的影响。结果表明:(1)白茅草和唐竹区的土壤pH值显著高于裸地区,但枫树和白檵木区的土壤酸化明显。(2)土壤有机质、活性有机质、全P、速效P等指标表现为乔木草本灌木,碱解N、全K、速效K表现为灌木乔木草本,全N表现为乔木灌木草本。(3)土壤综合肥力优劣为:枫树区梓树区白檵木区樟树区唐竹区白茅草区湿地松区板栗区裸地区,自然恢复植被比人工植被更有利于土壤肥力的提高。     

水蚀风蚀交错带植被恢复对土壤物理性质的影响

黄土高原北部晋陕蒙接壤区是典型的水蚀风蚀交错带和强烈侵蚀中心,探讨该区植被恢复对土壤性质的影响有助于该区植被恢复模式的合理选择和土壤生态效应的科学评价。以神木六道沟小流域为研究区域,探讨了土壤物理性质变化与植被恢复的关系。结果表明,研究区土壤容重、砂粒含量以及饱和导水率普遍较高,表层(0-20cm)均值依次为1.38gcm-3、44.2%和1.46mmmin-1,而土壤总孔隙度与粘粒含量则较低,表层均值分别为45.6%和2.4%,反映了研究区土壤荒漠化的严峻现状,其中北坡(迎风坡)表现尤为严重。与农田相比,采用自然弃耕、种植紫花苜蓿(Medicagosativa)和柠条(Caragana korshinskii)、恢复次生天然草地等不同的植被恢复模式可以不同程度地降低土壤容重,增加土壤总孔隙度、饱和导水率以及团聚体稳定性,改善土壤的物理性质,而且随着恢复时间(1-30a)的延长,这种效应会进一步增强。通过种植人工草地并使其自然恢复为次生天然草地的植被恢复模式,对土壤结构的改善作用显著优于直接种植柠条灌丛和自然弃耕等模式。但是,短期内(30a)植被恢复对土壤颗粒组成、比重等物理性状无显著影响,意味着土壤一旦出现沙化将很难逆转。从对植被恢复响应的敏感性而言,土壤容重、总孔隙度以及团聚体稳定性可以作为土壤生态效应评价的主要指标。     

露天煤矿排土场不同配置人工植被对草本植物物种多样性的影响

2012年8—9月对黑岱沟露天煤矿北排土场乔木、乔木+灌木、乔木+草本(禾本科)、乔木+草本(豆科)和撂荒地5种人工植被配置条件下草本植物种类和数量进行了调查。结果表明:撂荒地的植物物种多度为181.00±12.52,显著高于其他植被配置条件的物种多度;撂荒地和乔木+草本(豆科)配置的植物物种丰富度最高,分别为4.50±0.95和4.78±0.87,显著高于其他植被配置条件的物种丰富度。植物物种多度、丰富度与土壤有机质和全氮呈正相关,与磷含量呈显著负相关。增加排土场浅层土壤有机质和全氮含量,控制土壤磷的输入是促进露天煤矿排土场植物物种多样性恢复的有效措施。促进排土场草本植物多样性恢复,应优先考虑种植能够明显改善土壤质量的物种,如豆科植物。     

鸡西煤矿矸石山植被自然恢复规律及其环境解释

煤矿矸石山的植被恢复是矿区土地复垦的重要内容,也是退化生态系统与恢复生态学上极为关注的研究领域之一。鸡西是我国重要煤产区,煤矸石山占用和破坏了大量土地资源。因此,开展鸡西煤矸石山植被恢复研究意义十分重大。运用传统的植被样方调查方法获取煤矸石山自然恢复植被的基本状况,同时采用烘干法、电位法、凯氏定氮法、钼锑抗比色法、火焰光度法和外加热法等测定矸石山土壤的物理和化学性质,最后运用TWINSPAN、DCA、CCA、DCCA等植物分类与排序方法分析矸石植被梯度变化规律及其与环境因子之间的关系。结果表明,排矸50a以内的煤矸石山大致可以分为三大类:第Ⅰ类,排矸年龄小于10a的煤矸石山;第Ⅱ类,排矸年龄在12~30a的煤矸石山;第Ⅲ类,排矸年龄在30~50a的煤矸石山。DCA排序与TWINSPAN结果一致,随对角线因子变化矸石山排矸年龄增加;CCA和DCCA排序图明显反映出排序轴的生态意义,表明煤矸石山植物群落的梯度变化主要受土壤pH值、土壤养分和土壤的物理性质控制。因此,在人工加快煤矸石山植被恢复时,应以原始自然恢复植被为首选植物种类,不同煤矸石山阶段采用不同种类,同时辅以土壤的理化性质改良,能达到最佳效果。     

晋西北丘陵风沙区柠条林下草本植物群落组成和种群生态位变化特征

晋西北丘陵风沙区生态环境脆弱,是我国风沙活动危害最为严重的地区之一。为探究晋西北丘陵风沙区人工柠条林林下草本植物群落组成和种群生态位变化规律,以不同种植年限（撂荒地CK、6、12、18、40、50 a）人工柠条林林下天然草本植物群落作为研究对象,对其群落组成、重要值及种群生态位变化特征进行分析。研究结果表明：（1）不同年限柠条林下天然草本植物组成共记录到22科41属52种,其中,种植前期（0-6 a）林下草本植物以一年生草本植物为优势类群,伴有少数多年生草本植物（3种）;种植中期（12-18 a）林下草本植物主要由多年生草本植物（12种）为主,伴生有一年生草本植物（6种）及天然灌木（2种）组成;在种植后期（40-50 a）,林下草本植物依然以多年生草本植物（12种）为主。（2）在不同年限柠条林下,草本植物生态位宽度和生态位重叠发生明显变化,种植前期（0-12 a）的优势类群为一年生先锋物种（米蒿和野燕麦）,其生态位宽度最宽（9.46、9.34）,且与其他物种的生态位重叠程度最大（0.3、0.29）;而种植中后期（18-50 a）优势类群变为多年生草本植物,优势种披碱草与其他物种的生态位重叠程度最大（0.42）,说明其为林下植物群落主要的优势种和泛化种。（3）柠条林种植后期（50 a）,多数草本植物主要集中分布在生态位重叠系数DCA排序图的中心位置,说明在种植后期草本植物对相同环境的资源竞争激烈,林下草本植物群落处于演替过渡阶段。综上,人工种植柠条林相较于天然恢复（CK）,更有利于增加草本植物群落的多样性,但林下植物群落对资源的竞争更为激烈。这些研究结果对干旱半干旱地区风沙区植被恢复和生态重建具有重要的参考价值,对人工林生态恢复具有重要意义。     

锦屏水电站岩土渣场植被恢复的动态特征

植被恢复过程物种多样性的动态特征变化反映了植被的恢复程度。本研究以膨润土-纤维复合的岩土渣场植被恢复技术(CSR工程技术)作为岩土渣场植被恢复的应用背景,以锦屏二级水电站岩土渣场为对象,通过对植被恢复群落的调查和物种多样性分析,研究了岩土渣场人工恢复群落物种多样性动态特征。结果表明:初期选取的植物普遍表现出对环境的适应性,且豆科植物在群落中占据着主要的优势;随时间加长,禾本科、菊科等多年生草本植物逐渐增多,在群落功能维持中占据重要地位;群落动态与多样性关系紧密,随演替进展群落物种组成与物种多样性增加,群落生态优势度下降,而均匀度增加,群落渐趋稳定。     

不同植被恢复模式下煤矸石山复垦土壤性质及煤矸石风化物的变化特征

为了探讨植被恢复模式对煤矸石山复垦土壤和矸石风化物的影响,对煤矸石山6种主要植被类型(刺槐林、刺槐-柠条混交林、榆树-紫穗槐混交林、侧柏-刺槐混交林、荆条林、紫花苜蓿草丛)下土壤和煤矸石风化物的理化性状及重金属进行了比较研究。结果表明:(1)煤矸石山上种植植被可使土壤容重、土壤持水量和孔隙度明显改善。乔木模式更明显。矸石山植被恢复后,可明显增加土壤养分含量。不同植被模式下,土壤养分增加存在显著差异。侧柏-刺槐和榆树-紫穗槐混交模式效果较好。(2)植被对煤矸石风化物容重和机械组成改善作用依次为针阔混交林>乔灌林>乔木纯林>灌木林>草本。植被促进有机质与全氮积累依次为:侧柏-刺槐>刺槐>刺槐-柠条>榆树-紫穗槐>荆条>紫花苜蓿。荆条林下煤矸石风化物全P含量最大。荆条林与侧柏-刺槐混交林利于速效P积累。对速效K积累有利的是荆条林与榆树-紫穗槐混交林。(3)植被种植可以减少煤矸石风化物中重金属含量。榆树-紫穗槐混交模式对减低超标重金属Cd的效果好,其次是针阔混交林(侧柏-刺槐)。对于超标重金属As而言,侧柏-刺槐模式优于其它植被模式,基本达到重金属As不超标。     

三星堆遗址城墙不同维护措施下草本植物群落组成、生态位及稳定性特征

为了解三星堆遗址城墙植被分布特征和恢复现状，以三星堆遗址城墙5种典型群落为研究对象，采用生态位理论与改进的贡献定律法探讨不同维护措施(自然更新、种植、弃耕、灌木去除、修剪)下草本植物群落的稳定性及生态位特征。结果表明：研究区共记录草本植物87种，隶属于31科73属，以菊科及禾本科植物占优，多年生草本植物居多。不同维护措施下主要草本植物生态位宽度存在差异，自然更新和灌木去除措施下一年生草本植物生态位宽度值较高，种植、弃耕和修剪措施下多年生草本植物生态位宽度值较高。自然更新、灌木去除、修剪措施下草本植物的生态位重叠和相似性较高，种植措施下最小。重要值与生态位宽度呈显著正相关但排序并非完全一致；生态位宽度较大的物种产生生态位重叠的概率较大，生态位相似性较高。M-Godron稳定性结果表明，灌木去除和修剪措施与自然更新下群落稳定性相似，弃耕和种植措施下群落稳定性较差。综上，结合遗址城墙的植被特点和保护要求，建议实行以自然更新为主的原生境保护措施，必要时辅以科学的人工维护(灌木去除、修剪等),实现物种的合理配置，促进三星堆遗址城墙植被的可持续发展和原生态展现。     

渭北黄土高原人工刺槐林植物多样性动态

以陕西省永寿县人工刺槐林为研究对象,采用"空间序列代替时间序列"法,研究了人工刺槐林下植物群落的物种多样性特征.结果表明:(1)渭北黄土高原人工刺槐林下植被的演变依次经历了艾蒿(水蒿)、葎草、葎草+糙苏3种主要类型;主要建群种表现为一年生向多年生、低级向高级的演变趋势.(2)Patrick、Shannon-Wiener、Simpson和Pielou指数随刺槐林龄级的增加均呈现二次函数变化,说明该地区刺槐林林下植被通过自然恢复可达到相对稳定的状态,但该过程比较缓慢.(3)阴坡的各个多样性指数明显大于阳坡,说明阳坡生态修复的自然条件(主要是土壤水分条件)更差,植被自然恢复的速率更缓慢.研究表明,渭北黄土高原阳坡的生态修复应以选用耐旱植物或者以保护和恢复草本群落为主,仅在水分条件较好、能够满足乔木或灌木生长的小地形内进行适当比例的乔、灌、草复合配置,以丰富群落层次结构,优化群落生态功能.     

半干旱地区煤矸石山生态分类研究

半干旱地区煤矸石山生态分类研究张军,杨芳,林华（辽宁省阜新矿务局林业处,１２３００３）ＥｃｏｌｏｇｉｃａｌＣｌａｓｓｉｆｉｃａｔｉｏｎｏｆＣｏａｌＧａｎｇｕｅＨｉｌｌｓｉｎＳｅｍｉ－ＡｒｉｄＲｅｇｉｏｎｓ．￥ＺｈａｎｇＪｕｎ;ＹａｎｇＦａｎｇ;Ｌｉｎ...     

Primate and Dung Beetle Communities in Secondary Growth Rain Forests: Implications for Conservation of Seed Dispersal Systems

Conservation efforts are often aimed at one or a few species. However, habitat sustainability relies on ecological interactions among species, such as seed dispersal. Thus, a community-scale conservation strategy may be more valuable in some settings. We describe communities of primary (primates) and secondary (dung beetles) seed dispersers from 5 sites in the Brazilian Amazon. We estimate community biomass of these taxa and, using multivariate ordination, examine the potential for natural reforestation at each site, given the communities of seed dispersers present. Since disturbed habitat is increasingly common and increasingly the focus of conservation efforts, we also examine differences among seed disperser communities between primary forest and secondary growth at each site. Analyses of faunal biomass in different localities and habitats indicate that secondary growth receives nearly as much use by primates as primary forest; given the dominant groups of dung beetles in secondary growth, disturbed habitat should show a pattern of seed burial that is clumped and deep. Areas with high biomass of Alouatta spp. and the large nocturnal dung beetle species may have the greatest potential for natural reforestation of secondary growth particularly for large seeded species. The data suggest that knowledge of the biomass of primary and secondary dispersing fauna facilitates predictions for the likelihood of disturbed habitat to regenerate and comparisons of sites in broader geographical areas e.g., Neotropical vs. Paleotropical forests.     

典型农田退耕后土壤真菌与细菌群落的演替

土壤真菌和细菌作为地下生态系统的重要组成部分,其群落的恢复状况是评价农田退耕还林生态效益的重要指标。以云南省维西县典型退耕还林农田为对象,利用高通量测序等方法比较了不同退耕年限的农田土壤中真菌和细菌群落随植被演替的变化特征。结果发现,农田撂荒后土壤细菌多样性先显著降低后缓慢上升,真菌多样性变化不明显;地上部植被由草本经灌丛再向林地演替的过程中,土壤真菌的群落组成随植被变化呈现明显的改变,主要体现在粪壳菌纲(Sordariomycetes)所占比例的减少(由30%减至10%左右)和伞菌纲(Agaricomycetes)所占比例的增加(由5%以下增至20%以上);而细菌的群落组成无明显变化。聚类分析的结果显示,真菌的群落组成变化与植物群落的演替规律更为同步。不同演替阶段的退耕农田土壤真菌和细菌群落均明显区别于未经扰动的天然林,表明人为扰动对土壤微生物群落的影响可能在较长时间内持续存在。研究揭示了云南典型农田退耕后地下土壤真菌和细菌群落随植被演替的变化特征,为全面评价该地区退耕还林的生态效益提供了数据支撑。     

矿山复垦区土壤微生物及其生化特性研究

通过对矿区煤寿石凤化物上几种不同复垦措施的得垦区,进行一系列土壤微生物及其生化特性的分析研究,结果表明,各类和同生物菌群、数量以及生物活性强度、放线菌和真菌的优势种属、土壤养分等均 中植区大于不覆上区,豆科区大于禾本科区;而覆上厚度（１０～２０ｃｍ范围）对土壤养分、生理厚度（１０～２０ｃｍ范围）对土壤养分、生理群微生物及其活性等影响较小,可见覆江层土（１０ｃｍ左右）种植豆科植物是矿区复垦中一项快速     

Plant community development following reclamation of oil sands mines using four cover soil types in northern Alberta

Understanding the effects of reclamation treatments on plant community development is an important step in setting realistic indicators and targets for reclamation of upland oil sands sites to forest ecosystems. We examine trends in cover, richness, evenness, and community composition for four cover soil types (clay over overburden, clay over tailings sand, peat‐mineral mix over overburden, and peat‐mineral mix over tailings sand) and natural boreal forests over a 20 year period in the mineable oil sands region of northern Alberta, Canada. Tree, shrub, and nonvascular plant species cover showed similar increases over time for all reclamation treatments, with corresponding declines in forb and graminoid cover with time. These trends resemble those in the natural boreal forests of the region and the trajectory of community development for the reclamation treatments appears to follow typical early successional trends for boreal forests. Species richness and diversity of natural forest differed significantly from reclamation treatments. Nonmetric multidimensional scaling ordination and multi‐response permutation procedure revealed that species composition was not affected by reclamation treatment but clearly differed from natural forest. Analysis of species co‐occurrence indicated random plant community assembly following reclamation, in contrast to a higher proportion of nonrandom plant community assembly in natural forests. Thus, reclaimed plant communities appear to be unstructured through year 20 and assembly is still in progress on these reclaimed sites.     

Microtopography Influences Early Successional Plant Communities on Experimental Coal Surface Mine Land Reclamation

Surface mining for coal represents one of the dominant forms of anthropogenic disturbance to forests of the eastern United States. Reclamation methods adopted under federal law in the 1970s have led to a state of arrested succession, failing to achieve pre‐disturbance conditions. New methods of reclamation have been proposed with the goal of returning mined land to its former forested state through the use of compaction reducing techniques that significantly increase fine‐scale heterogeneity. The Forestry Reclamation Approach creates topographic heterogeneity by loosely dumping overburden material into large piles to serve as a tree‐planting medium. We examined the effect of fine‐scale topographic relief, soil physical properties, and reclamation method on early plant community development on a mine site in eastern Ohio. We sampled plots at four microtopographic positions and three distances from the remaining forest edge in both experimentally and traditionally reclaimed areas of a surface mine. Multivariate analysis of variance (ANOVA) on distance matrices indicated significant differences in plant community composition among microtopographic positions and reclamation methods. Microtopographic positions also exhibited significant differences in measured soil properties significantly affecting plant community composition. Plots in the traditionally reclaimed areas had no woody plant colonization, indicating arrested succession common to sites reclaimed using traditional methods. Our results suggest that the creation of topographic heterogeneity at the time of reclamation markedly accelerates ecological succession and promotes enhanced plant community diversity. Expanded application of the methods used here could allow for a faster return to the former forested state of mined lands than traditional reclamation methods.     

Using community viability analysis to identify fragile systems and keystone species

Owing to interdependences among species in ecological communities, the loss of one species can trigger a cascade of secondary extinctions with potentially dramatic effects on the functioning and stability of the community. It is, therefore, important to assess the risk and likely extent of secondary extinctions. Community viability analysis is a new technique that can be used to accomplish this goal. The analysis can also be used to identify fragile community structures and keystone species and, hence, to provide guidelines for conservation priorities. Here, we describe the principles underlying community viability analysis and review its contributions to our understanding of the response of ecological communities to species loss.     

Community Characteristics of Early Recovery Vegetation on Abandoned Lands of Shifting Cultivation in Bawangling of Hainan Island, South China

Shifting cultivation is a major form of agricultural practice in most parts of tropical regions worldwide. In places where the bush fallow period is excessively shortened or the period of cultivation is extended for too long, the rate of vegetation recovery and biodiversity on abandoned lands of shifting cultivation would decline. The recovery of the secondary plant communities could even be inhibited for a prolonged period because of grass occupancy. Because of the vital significance of the early recovery communities to secondary succession, we studied the community characteristics of early recovery vegetation on abandoned lands of shifting cultivation in Bawangling of Hainan Island. Measurements were made of the community composition and structure of early recovery vegetation. The sprouting abilities of different functional groups and different species in the same functional group, and the effect of the grass functional group on the composition and quantitative characteristics of tree and shrub functional groups were analyzed. Results indicated that only a few families, genera, or species apparently dominated in the early recovery vegetation on the abandoned lands of shifting cultivation and that deciduous species occurred with a rather high percentage in this early recovery community compared with the natural secondary or old growth forests. Smallsized individuals dominated the woody community. The abundance and basal area of sprouting stems for species in the tree functional group were greater than those of seeder stems, whereas the abundance and basal area of resprouters and seeders for species in the shrub functional group did not differ. The total abundance of stems for the community, stem abundances for species in tree or shrub functional groups, and for seeder or resprouter stems were all negatively correlated with coverage of the grass functional group. The mean sprouting ability in the tree functional group was greater than in the shrub functional group. The sprouting ability for different species in the same functional group was also significantly different.     

Litter and soil arthropod colonization in reforested semi‐deciduous seasonal Atlantic forests

The recovery of soil ecological processes during the restoration of tropical forests is greatly influenced by arthropods that live in the litter and soil. However, these communities present complex dynamics, and their colonization patterns are not well understood. In this study, we examined the response patterns of litter and soil arthropods to the ecosystem regeneration process by assessing reforestation sites from two regions of São Paulo State, Brazil, and we compared the data obtained from these sites with data from mature forests. We assessed the arthropod communities using similarity indices and high‐level taxa abundance, with the level of forest succession and the locations of the restoration areas as factors. Forest succession correlated with the species composition as communities from the reforestation sites gradually became more similar to communities from the mature forests, while their quantitative patterns were minimally related. Forest maturation positively affected the richness of the litter community and the abundance of some minor groups, such as Protura, Diplura, and Symphyla. The region influenced the species composition but did not influence the manner in which the communities changed during the maturation process. We also found a convergent soil colonization pattern as arthropod communities from different sites became more similar during forest succession. This finding is consistent with both empirical data and theoretical predictions from the specialized literature, although the subject has been poorly explored until now. We conclude that reforestation allows the colonization of soil and litter fauna in a biased manner.     

黔中煤矿区矸石堆场周边土壤藻类群落变化及其影响因素

通过对贵阳市花溪区麦坪乡煤矿区矸石堆场周边土壤进行采样分析,研究了煤矸石影响下土壤藻类群落组成和生物量的变化以及生物量、物种多样性指数与土壤因子之间的相关关系。结果表明:该区自然土壤藻类共计5门43属,其中蓝藻门(Cyanophyta)13个属、绿藻门(Chlorophyta)17个属、硅藻门(Bacillariophyta)7个属。受煤矸石污染后,土壤藻类的种类和数量明显减少,污染严重区域土壤藻类中蓝藻门仅有3个属、绿藻门4个属;香浓指数与有效铁、有效锰及速效磷含量之间存在极显著的相关性;物种丰富度与pH值和速效磷含量呈显著相关。污染严重区土壤藻类叶绿素a含量比对照区减少了93.1%;藻类生物量与pH值呈显著正相关,与有效铁含量呈显著负相关。调查区内土壤pH值和有效铁含量是影响土壤藻类生长的重要因子。